The erection of low rise, slab foundation buildings has been simplified by development of modular construction techniques. Such low-rise buildings are used typically as houses, warehouses, office buildings, and stores in shopping centers. Some such buildings are typically erected on poured concrete slab foundations. With conventional construction techniques, stud walls are prepared and secured to the foundation. The walls support rafters that span the foundation, and a roof is secured to the rafters. Interior walls subdivide the foundation and further support the rafters. Such a stick-frame building is closed-in by installing siding of various materials. Typically, several layers of siding materials are used, and these include fiber insulation boards, construction board sheets, and exterior skin materials such as brick, concrete, or wood siding. Insulation as appropriate is installed on the interior spaces between the studs. The interior walls are then typically closed with sheets of dry wall material.
Such extensive work typically required for on-site construction of stick-frame building is laborious, expensive, and time consuming. Weather conditions may also delay the construction schedule until the building is closed in.
Modular construction techniques, however, overcome some of these problems. These techniques include the use of modular panels for assembling the exterior walls. Generally, the modular panels include a support frame and an exterior skin. The modular panels are positioned in sequence around the foundation and are joined together. The exterior wall accordingly is closed-in as the building is assembled. U.S. Pat. No. 4,291,513 issued to Ankarswed describes a wall construction unit for buildings. A reinforced concrete layer constitutes the exterior face of the building. Longitudinal flanges extend from the concrete layer toward the interior of the building. Joists and intermediate insulation join the free end of the flanges and insulation is placed in the spaces between adjacent flanges. The insulation prevents formation of cold bridges between the exterior and interior of the building. The wall construction unit also includes a prolonged portion of the concrete layer extending from one flange, an intermediate portion extending from the end of the prolonged portion at right angles and parallel with the flanges, and a terminating flange extending at right angles from the end of the intermediate portion inwardly towards the adjacent flange. In cross-sectional view, these flanges in the prolonged portion partially close a substantially rectangular space which is filled with insulation. This rectangular section of the wall unit facilitates forming corners with a pair of such wall units.
U.S. Pat. No. 4,037,381 issued to Charles describes a panel with an exterior stucco surface. The panel attaches to adjacent studs of a building wall. The panel comprises a rectangular metal frame, a stucco sheet, and a plurality of metal tabs attached to the longer sides of the metal frames at vertically spaced intervals. The panel is assembled by placing the frame on a support with a sheet of felt paper in the frame. Cementitious material is poured onto the paper and cured. A rib lath is set on top and a second layer of cementitious material is poured. The cured panels are fastened to the framing studs by nailing through the metal tabs into the stubs.
U.S. Pat. No. 3,952,471 issued to Mooney describes prefabricated wall panels for a building. The building is constructed of load-bearing wall panels in combination with in-fill wall panels. The load-bearing panels include an integral subground level portion. This lower portion forms the foundation wall and rests on the footing of the building. In cross-sectional view, the load-bearing panels define a U-shape. A pair of flanges are disposed vertically on the side edges of the panel. The flanges constitute support columns for carrying the weight of the roof of the building. The space between the flanges is used for a pipe chase, air duct, recess for a sink unit, shelf space or insulation. As with standard construction, the space may also be covered by attaching interior wall panels to the free ends of the flanges. The load-bearing panels are positioned on the foundation on a steel angle embedded in the footing. A portion of the footing projects upward. A bolt also extends upward from the footing. The bottom front edge of the panel is welded to the portion extending upwardly from the footing. The back of the panel receives the bolt. A levelling nut is turned on the bolt to level the panel and is secured by welding the nut on the bolt. The in-fill panels are precast of reinforced concrete and preferably contain the window and door openings. The in-fill panels are positioned between and secured to a pair of load-bearing panels.
U.S. Pat. No. 4,842,669 issued to Considine describes a structural wall panel and method of assembly of such a panel. The panel includes a rigid insulating material to which studs and an exterior wafer board panel are bonded. The panels are manufactured by applying an adhesive to the wafer board panel, positioning the wafer board panel on top of a stud wall, and pressing the wafer board panel into the stud wall for a pre-determined time to secure the wafer board panel to the stud wall.
U.S. Pat. No. 4,481,743 issued to Jellen describes a construction method that erects pre-formed panels on a foundation of the building. The panels are mounted on carrier assemblies that travel in a track around the exterior of the foundation. Once the panels are in position, leveling bolts in the base of the panel are backed out to engage the upper surface of the track. Cementitious material is poured around the track and the base of the panel to firmly lock the panels and their supporting carrier assemblies into place.
Such known modular panels and systems for installing modular panels have drawbacks which reduce the benefits that are expected from modular construction techniques. These drawbacks include low insulative characteristics of the panels, construction time and labor that decreases the advantages of modular construction, complications with assembly of the panels into a wall, and panels that are not readily adapted to include window and door openings. For some panels, insufficient insulative properties of the assembled panel requires on-site addition of insulation. This additional labor and expense at a job site is eliminated by a modular panel designed with improved insulative characteristics.
For some modular panels, construction assembly is time consuming and labor intensive. Special connecting and leveling members are included in the panels, thereby increasing the cost and complexity of the panels. The modular panel should reduce overall labor and construction time to reduce the cost of the building construction.
Related to this is on-site assembly of the panels into an exterior wall. Some panels have complicated interlocking flanges and support frames. These complicated assemblies are labor intensive to align the panels, level the panels, and join the panels together and to the foundation. Some wall panels made substantially entirely of concrete are heavy and require cranes to lift and move the panels.
Some known modular buildings have windowless exterior walls. As discussed above, it is known to provide an in-fill panel to accommodate windows and doors. The modular panel should easily be adaptable to accommodating windows and doors. This will provide flexibility in designing office buildings and houses using these modular panels.
Accordingly, there exists a need in the art for a modular panel for assembling exterior walls that has improved insulative characteristics, reduces labor and time to manufacture, is readily and easily assembled, and accommodates placement of windows and doors.